Genetic Diversity and DNA Fingerprint of Cassava (Manihot esculenta Crantz.) Using SSR Markers

Abstract

The genetic diversity of cassava is an important information for conducting research and development to improve cassava variety. This research aimed to assess the genetic diversity and to analyse clusters of 270 cassava varieties from DOA germplasm collection at Rayong Field Crops Research Center, Department of Agriculture using 16 fluorescent-labeled SSR markers. Results showed that 16 SSR markers were able to differentiate well in the cassava genome, generating polymorphic alleles in total of 88 alleles varying from 3 – 9 alleles per locus, with an average of 5.5 alleles per locus. All 88 alleles showed the polymorphic bands accounted for 100%. Sizes of DNA fragments ranged from 100 – 418 base pairs. The Polymorphism Information Content (PIC) value ranged from 0.38 – 0.78, with an average of 0.63. Cluster analysis based on UPGMA and genetic relationships using NTSYSpc version 2.10e showed similarity in coefficient value in range of 0.10 – 1.00, and revealed 3 major distinct groups, consistent with pedigree and geographical locations, with cophenetic correlation (r) of 0.70. Therefore, SSR markers in this study were suitable for identifying the genetic differences of cassava varieties, and the genetic diversity database of cassava is useful for parental selection in cassava breeding programs.